JP2001196732A - Cream solder dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cream solder dispenser for forming a uniform cream solder coating on a circuit board with a uniform coating quantity. SOLUTION: The cream solder dispenser coats a circuit board B with cream solder, by squeegeeing cream solder mounted on a panel 36 by means of a squeegee body 44 and pushing it out from a nozzle 34 provided on the panel. The squeegee body comprises a planar perforated squeegee, extending downward through a spacer, and a return squeegee. The perforated squeegee comprises a lower end squeegee cutter positioned on the panel through a gap, and a through-hole, extending in the moving direction of the perforated squeegee. The return squeegee comprises a lower end squeegee cutter extending downward of the lower end squeegee cutter of the perforated squeegee and touching on the panel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispenser used for applying a cream solder to a circuit board, and more particularly, to a dispenser which remains on the surface of a panel when squeezing with a squeegee. The present invention relates to a dispenser device, in particular, a multi-spot dispenser device, in which the amount of cream solder is reduced to prevent the performance of the cream solder from being deteriorated.

[0002]

2. Description of the Related Art A circuit board is a board for mounting electronic components on which a wiring pattern for soldering electronic components is mounted. The cream solder is applied to the wiring pattern, and the electronic components are mounted by soldering. It has become.

[0003] Here, referring to FIG.
A configuration of a conventional multi-spot dispenser device as disclosed in Japanese Patent Application No. 2775 and a method of using the same will be described. FIG. 7 is a schematic cross-sectional view showing the configuration and operation of a main part of a conventional multi-spot dispenser device. As shown in FIG. 7, a conventional multi-spot dispenser device 10 includes a panel 12 on which a cream solder is placed on a panel surface, and a cream solder that is press-fitted so as to protrude from the lower surface of the panel 12 and is perpendicular to the panel surface. There is provided a nozzle 14 for discharging, and a squeegee 16 for squeezing the cream solder C on the panel surface and pushing it out of the nozzle 14. When applying the cream solder C to the circuit board B, the cream solder C is placed on the panel 12 and FIG.
7, the squeegee 16 is moved from the right-hand side to the left-hand side in FIG. 7 to squeeze the cream solder C and push out the cream solder C from the nozzle 14, and the cream solder is applied to the circuit board B facing the lower surface of the panel 14. Coated.

Then, a cream solder C is applied with a squeegee 16.
When squeezing is performed, the squeegee 16 is operated so that the cream solder remains on the panel 12 at a predetermined thickness. When the squeegee 16 is brought into contact with the panel 12 to squeeze the cream solder C, the cream solder particles are crushed, and the crushed particles are clogged in the nozzle 14, and the nozzle 1
No cream solder comes out of No. 4 and cannot be applied. Therefore, conventionally, the squeegee 16 is positioned so as to have a gap on the panel 12 and squeezed, and the
2, a cream solder layer having a predetermined thickness is left. Also, by adjusting the gap between the panel surface and the tip of the squeegee 16, the applied amount of cream solder can be adjusted, so that the cream solder layer is left on the panel 12.

[0005]

However, when cream solder is applied to a circuit board using a conventional multi-spot dispenser, there are the following problems.
A first problem is that the amount of the cream solder applied on the circuit board is reduced while the cream solder is applied on the circuit board using the multi-spot dispenser device. The second problem is that when the cream solder applied to the circuit board is reflowed, the temperature of the cream solder is about 100 ° C., and steam is generated from the cream solder.
Since the solder does not melt and solidify in a stable state, defective bonding or the like occurs. A third problem is that it is difficult to form a uniform and uniform quality cream solder coating film. The fourth problem is that when the inner diameter of the nozzle is small, for example, when the inner diameter is 1.0 mm or less, it is difficult to extrude the cream solder from the nozzle, so that the cream solder cannot be applied, or in a stable state. This is a problem that the coating cannot be performed.

Accordingly, an object of the present invention is to provide a cream solder dispenser capable of forming a cream solder coating film of uniform and uniform quality on a circuit board with a uniform coating amount.

[0007]

Means for Solving the Problems The present inventor has set forth the above-mentioned first method.
Pursued the cause of the fourth problem, and obtained the following knowledge. The first to third problems are all due to the cream solder remaining on the surface of the panel.

The first problem is caused by the fact that a solvent such as a flux volatilizes from the cream solder remaining on the surface of the panel. Cream solder contains metallic substances such as lead, tin, and solvents such as flux.Solvents such as flux are volatile, and volatilize from the cream solder remaining on the panel to form a cream. The viscosity of the solder gradually increases. Since the high-viscosity residual cream solder is mixed with the added new cream solder, the cream solder has a high viscosity and is difficult to be extruded from the nozzle, and the application amount is reduced. The larger the area exposed to air, the easier the flux is to volatilize. Therefore, if the cream solder is left in a thin layer on the surface of the panel as in the related art, this problem becomes more remarkable.

[0009] The second problem is caused by moisture absorption of the cream solder remaining on the surface of the panel. That is, the cream solder remaining on the panel surface comes into contact with air and absorbs moisture in the air. When the cream solder that has absorbed moisture is reflowed, steam is generated from the cream solder when the temperature of the cream solder is about 100 ° C., and the solder does not melt and solidify in a stable state, so that defective bonding or the like occurs.

[0010] The third problem is also caused by the fact that the cream solder remaining on the surface of the panel is mixed with fresh cream solder and pushed out of the nozzle. When applying the cream solder, the cream solder remaining on the panel is not rolled, so the old cream solder and the newly added new cream solder are mixed together in a lump, and as a result, the cream solder pushed out from the nozzle, Loss of uniformity.

A fourth problem is that, in the conventional multi-spot dispenser device, the squeegee is constituted by a single-stage squeegee. This is because it becomes difficult to push the cream solder from the nozzle due to friction between the nozzle and the inner wall of the nozzle.

As described above, the first to third problems that occur in the conventional multi-spot dispenser device are caused by the cream solder remaining on the surface of the panel after driving the squeegee. Therefore, the present inventor considers that it is necessary to prevent the cream solder from remaining on the surface of the panel, and scrapes off the cream solder remaining on the surface of the panel after squeezing with a squeegee, and collects the cream solder in front of the squeegee. The present invention was completed through repeated experiments with the idea of returning to the above.

In order to achieve the above object, based on the above findings, a cream solder dispenser according to the present invention is provided on a panel by squeegeeing cream solder placed on the panel with a squeegee. In a cream solder dispenser device that extrudes from a nozzle and applies cream solder to a circuit board, a squeegee is provided with a plate-shaped perforated squeegee extending downward from the spacer via a spacer, and a return squeegee. The squeegee has a lower end squeegee blade located on the panel with a gap, and a through hole penetrating in the moving direction of the perforated squeegee, that is, in the squeezing direction, and the return squeegee is lower than the lower end squeegee blade of the perforated squeegee. It has a lower end squeegee blade that extends downward and contacts the panel. There.

According to the present invention, the cream solder on the panel is squeezed with the lower end squeegee blade of the perforated squeegee and extruded from the nozzle, and the cream solder remaining on the panel is scraped with a return squeegee having a squeegee blade closely attached to the panel surface. Take and store in the space below the spacer between the return squeegee and the perforated squeegee, and return from the through hole in the perforated squeegee to the cream solder pool in front of the perforated squeegee. Thus, unlike the conventional dispenser device, no cream solder remains on the surface of the panel.

In a preferred embodiment of the present invention, the return squeegee is provided with a position adjusting device for adjusting the position of the lower end squeegee blade so that the lower end squeegee blade contacts the panel. Thereby, the cream solder remaining on the panel can be reliably scraped off with the squeegee blade. In another preferred embodiment of the present invention, a fixing means is provided for fixing the perforated squeegee so that the lower end squeegee blade of the perforated squeegee maintains a constant angle with respect to the panel. This makes it possible to keep the amount of extrusion from the nozzle constant and to keep the thickness of the cream solder coating film constant.

In still another preferred embodiment of the present invention, the perforated squeegee is made of POM (Polyoxymethylene, polyoxymethylene / acetal resin) or a material having the same hardness as POM, and the return squeegee is made of urethane or It is formed of a material having the same hardness as urethane. By forming the perforated squeegee with a material having a high hardness such as POM, the abrasion of the perforated squeegee is prevented, and by forming the return squeegee with a soft material having a low hardness such as urethane, the particles of the cream solder are removed. Without crushing
The cream solder remaining on the panel can be scraped off.

[0017] Preferably, the perforated squeegee also has a squeegee blade at the upper end. Thus, when the lower squeegee blade is worn, the upper squeegee blade can be used.

More preferably, the perforated squeegee is configured as a combined perforated squeegee in which a plurality of perforated squeegees are stacked in the squeegee direction. By using a multi-stage perforated squeegee, the application amount of the cream solder can be increased. If the nozzle has the same inner diameter, the application amount can be increased to about 1.2 to 1.5 times the application amount when a single-staged squeegee is applied when a multi-stage perforated squeegee is applied. . Therefore, since the cream solder having the same application amount as the conventional one can be applied using the nozzle having a small inner diameter, it is possible to meet the demand for the application with a smaller application pitch than the conventional one.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the accompanying drawings based on examples of embodiments. FIG. 1 is a side view showing a configuration of a multi-spot dispenser device according to an example of the present embodiment, FIG. 2 is a side view showing a configuration of a squeegee operating body, and FIGS. 3 (a), (b) and (c) are respectively FIG. 4 is a perspective view, a side view, and a front view showing a configuration of a perforated squeegee, and FIG. 4 is a perspective view showing a configuration of a return squeegee. As shown in FIG. 1, the multi-spot dispenser device 30 according to the embodiment of the present invention is arranged on a base 32 for supporting a squeegee mechanism for squeegeeing cream solder on a panel surface, and is disposed on the base 32 and extends downward. A panel 36 having nozzles 34; a receiving table 38 disposed below the base 32 for mounting the circuit board B;
And a transfer device 42 that transfers the circuit board B onto the support 38.

As shown in FIG. 1, the squeegee mechanism includes two squeegee bodies 44A and 44B and two squeegee bodies 44.
And a horizontal driving device 45 for driving A and B in the horizontal direction. As shown in FIG. 1, the squeegee main bodies 44A and B include squeegee operation units 46A and B, and support units 47A and B that support the squeegee operation units 46A and B, respectively.
A squeegee drive cylinder 48A provided on each of the support portions 47A and 47B to raise and lower the squeegee operation portions 46A and 46B,
B.

As shown in FIG. 2, the squeegee main bodies 44A and 44B are provided with an L-shaped squeegee fixing plate 49 and a return squeegee 52 and a return squeegee 52 fixed to the squeegee fixing plate 49 with a spacer 50 therebetween. Perforated squeegee 54
And The squeegee fixing plate 49 is connected to the lower end of the squeegee drive cylinder 48, and the squeegee main body 44A,
B moves up and down.

The return squeegee 52 has a squeegee blade at the lower end as shown in FIGS. 2 and 4, and is a plate-like body made of a soft material such as urethane so as not to crush the particles of the cream solder. is there. The perforated squeegee 54 is shown in FIG.
As shown in (a) to (c), it is formed of a material having high hardness such as POM so as not to be deformed at the time of squeezing.
The cross section is a plate-like body having a substantially parallelogram shape, and has a horizontally long through hole 58 in a central portion in two upper and lower stages and two right and left rows, and a squeegee blade at an upper end and a lower end. Thus, when the lower end squeegee blade is worn out due to long-term use and good squeezing cannot be performed, the upper end squeegee blade can be used. The horizontally long through hole 58 functions as a hole for returning the cream solder as described later, and penetrates in the moving direction of the squeegee, that is, the direction parallel to the longitudinal direction of the panel surface, as shown in FIG. As shown in (c), the hole is a horizontally long hole parallel to the horizontal direction of the panel surface.

The return squeegee 52 and the perforated squeegee 54 are respectively mounted on the squeegee fixing plate 4 as follows.
9 is attached. The perforated squeegee 54 is fixed to the vertical plate portion 62 of the L-shaped squeegee fixing plate 49 and the spacer 50 by a mounting screw 60 that penetrates a through hole of the perforated squeegee 54, and the angle of the lower end squeegee blade is constant. Is to be kept. Return squeegee 5
2 is fixed to the spacer 50 via an L-shaped return squeegee fixing plate 64.

As shown in FIGS. 2 and 4, the return squeegee 52 has a step at the top, and an L-shaped return squeegee fixing plate 64 composed of a horizontal portion and a vertical portion is superimposed on the step. Are combined. The return squeegee fixing plate 64 has a horizontal portion fixed at one end to the spacer 50 and a vertical portion connected to the return squeegee 52. As shown in FIG. 4, a tap hole 68 for screwing a height adjusting screw 66 for adjusting the height of the return squeegee 52 is provided in a horizontal portion of the return squeegee fixing plate 64. The height adjusting screw 66 is screw-connected through the tapped hole 68, the lower end thereof is in contact with the upper surface of the return squeegee 52, and the upper end is rotatably connected to the horizontal portion 69 of the L-shaped squeegee fixing plate 49. .

A vertical hole of the return squeegee fixing plate 64 is provided with a through hole 72 through which a mounting screw 70 for fixing the return squeegee 52 to the spacer 50 passes. The return squeegee 52 is fixed to the spacer 50 by a mounting screw 70 that passes through a through hole 72 of the return squeegee fixing plate 64 and then through a vertically long hole (not shown) provided on the upper part of the return squeegee 52. still,
The spacer 50 is provided with a screw hole for screwing the mounting screw 70. By turning the height adjusting screw 66 to adjust the vertical position of the return squeegee 52 within the range of the length of the elongated hole of the return squeegee 52, the return squeegee 52 is brought into contact with the panel 36, and
Gap between the panel and the panel 36 can be eliminated.

As shown in FIG. 1, the squeegee operating portions 46A and 46B are located on the outside with the return squeegees 52 facing each other.
4 are arranged so as to be located, are integrally connected, and are driven by a horizontal driving device 45 to move in the horizontal direction.

The horizontal drive unit 45 holds the squeegee bodies 44A and 44B integrally connected and moves the endless belt 73 horizontally, and the endless belt 73 is rotated by a drive motor (not shown) to drive the endless belt 73. Drive side pulley 74, a guide pulley 76 on the opposite side of the drive side pulley 74 to guide the running of the endless belt 73, and the squeegee main bodies 44 A, B
And a guide rail 78 for guiding the horizontal traveling of the vehicle.
When the drive pulley 74 is rotated by the drive motor,
The endless belt 73 runs, and thereby the squeegee body 44
A and B move to predetermined positions while being guided by the guide rail 78.

The transport device 42 for transporting the circuit board B onto the receiving table 38 is a known transport device, and has a stopper 80 for stopping the transported circuit board B at a predetermined position. In FIG. 1, reference numeral 82 denotes a housing of the multi-spot dispenser device 30.

A method of using the multi-spot dispenser 30 according to the embodiment of the present invention will be described with reference to FIGS. First, a panel 36 having a nozzle 34 is mounted on a base 3.
2, and then a predetermined amount of cream solder C is placed on the panel 36. This completes the preparation work.

Next, the circuit board B is transported by the transport device 42, and the circuit board B is stopped at a predetermined position by the stopper 80 to perform positioning. Next, the pedestal driving cylinder 40 is operated to raise the pedestal 38, the circuit board B is placed on the pedestal 38, and stopped at a predetermined position below the panel 36. continue,
Squeegee drive cylinder 4 of squeegee body 44A in first row
8A is operated to lower the squeegee operating unit 46 and stop the squeegee operating unit 46 at the set position.

Next, the drive motor is started to run the endless belt 73, and the squeegee body 44A is moved from right to left or from left to right, and is moved by the perforated squeegee 54 as shown in FIG. The cream solder C on the panel 36 is squeezed and pushed into the nozzle 34 and discharged from the nozzle 34 onto the circuit board B. When the perforated squeegee 54 passes over the nozzle 34, the cream solder C remains on the panel 36 as shown in FIG. The remaining cream solder C is scraped off by the moving return squeegee 52, and the scraped cream solder C accumulates under the spacer 52 between the perforated squeegee 54 and the return squeegee 52, and the accumulated cream solder C
Is pushed back into the cream solder pool on the front surface of the perforated squeegee 54 through the horizontally long through hole 58 of the perforated squeegee 54. After moving a predetermined distance, the squeegee operating unit 4
6A is raised to a predetermined position by a squeegee drive cylinder 48A.

Next, the pedestal driving cylinder 40 is operated to lower the circuit board B on the pedestal 38 on which the cream solder C has been applied to the transport position, and place it on the transport device 42 to carry it out. Subsequently, the cradle drive cylinder 40 is driven to further lower the cradle 38 and stop at a predetermined position.

Subsequently, the second circuit board B is transported and positioned at a predetermined position by the stopper 80. next,
The pedestal 38 is raised by the pedestal drive cylinder 40, and the circuit board B is placed on the pedestal 38 and stopped at a predetermined position below the panel 36. Next, the squeegee driving cylinder 48B of the squeegee main body 44B in the second row is operated to operate the squeegee operating body 46B.
To stop at the set position. The drive motor is activated to drive the endless belt 73 in the direction opposite to the direction of the first row of squeegee bodies 44A,
B is moved from right to left or from left to right, and the perforated squeegee 54 applies the cream solder C on the panel 36 to the nozzle 3.
Extrude from 4. Hereinafter, the coating operation is performed in the same manner as in the squeegee body 44A in the first row.

When applying the cream solder C in a continuous operation, the above-described operations after the preparation operation are repeated.

When applying the cream solder to one circuit board B, the squeegee main body 44A is moved from right to left, and then the squeegee main body 44B is moved from left to right to apply the cream solder to one circuit board B. The reciprocating application can greatly reduce the variation in the amount of the cream solder C applied.

Modification of the Example of the Embodiment When the number of perforated squeegees 54 is one, FIG.
As shown in (a), the amount of the cream solder C applied is limited. Therefore, when a multi-stage squeegee type multi-spot dispenser device in which two or three perforated squeegees 54 are combined and used is used, the application amount of the cream solder C is increased as shown in FIG. I can do it. The multi-stage squeegee type can be applied to a squeegee of a conventional multi-spot dispenser device.

[0037]

According to the structure of the present invention, the cream solder remaining on the panel is scraped off by the return squeegee, and the scraped cream solder is returned to the cream solder pool in front of the perforated squeegee through the through hole. Therefore, it is possible to prevent the cream solder from being left on the surface of the panel. This produces the following effects. (1) Unlike the conventional case, the cream solder remaining on the panel and having the volatilized flux is not pushed out from the nozzle, so that the change in the viscosity of the cream solder is prevented, and the applied amount of the cream solder is stabilized. (2) The area of the cream solder that comes into contact with air is reduced, and moisture absorption is reduced. Therefore, splashing hardly occurs at the time of reflow, and soldering of a stable shape can be performed. (3) Since a structure is provided in which the cream solder is not left on the panel surface, the cream solder is constantly rolled during operation of the dispenser device. Therefore, the properties of the cream solder are always constant, and stable soldering is possible. (4) The application amount of the cream solder increases due to the multi-stage squeegee without holes. In other words, even with a nozzle having the same inner diameter as the conventional dispenser device, the amount of applied cream solder can be increased as compared with the conventional dispenser device. In addition, since a nozzle having a small inner diameter can be used, cream solder can be applied at a narrow pitch.

[Brief description of the drawings]

FIG. 1 is a schematic side view illustrating a configuration of a multi-spot dispenser device according to an example of an embodiment.

FIG. 2 is a side view showing a configuration of a squeegee operation body.

FIGS. 3 (a), (b) and (c) show, respectively,
It is the perspective view, side view, and front view which show the structure of a perforated squeegee.

FIG. 4 is a perspective view showing a configuration of a return squeegee.

FIG. 5 is a schematic side view illustrating functions of a squeegee operation body.

FIGS. 6A and 6B are schematic diagrams showing a state of applying cream solder by a single-stage squeegee and a multi-stage squeegee, respectively.

FIG. 7 is a schematic side view showing a configuration of a main part of a conventional multi-spot dispenser device.

[Explanation of symbols]

10: Conventional multi-spot dispenser device, 12
... Panel, 14 ... Nozzle, 16 ... Squeegee, B ...
... Circuit board, C ... Cream solder, 30 ... Multi-spot dispenser device of the embodiment example, 32 ... Base, 34 ... Nozzle, 36 ... Panel, 38 ... Cradle,
40 ... Cradle drive cylinder, 42 ... Transfer device, 44 ...
... Squeegee main body, 45 ... Horizontal drive unit, 46 ... Squeegee operating unit, 47 ... Support unit, 48 ... Squeegee drive cylinder, 49 ... Squeegee fixing plate, 50 ... Spacer,
52: Return squeegee, 54: Perforated squeegee,
58 ... horizontally long through hole, 60 ... mounting screw, 62 ...
... vertical plate, 64 ... return squeegee fixing plate, 66 ...
… Height adjustment screw, 68… Tapped hole, 70… Mounting screw, 72… Through hole, 73… Endless belt, 74…
Drive-side pulley, 76 guide pulley, 78 guide rail, 80 stopper, 82 housing.

Claims (6)

[Claims] 1. A cream solder dispenser device in which cream solder placed on a panel is squeezed with a squeegee, extruded from a nozzle provided on the panel, and coated with cream solder on a circuit board. A plate-shaped perforated squeegee extending downward from the spacer via the spacer, and a return squeegee are provided.The perforated squeegee has a lower end squeegee blade located on the panel via a gap, and a moving direction of the perforated squeegee. A cream solder dispenser device, having a through hole that penetrates, wherein the return squeegee has a lower end squeegee blade that extends below the lower end squeegee blade of the perforated squeegee and contacts a panel. 2. The return squeegee according to claim 1, further comprising a position adjusting device for adjusting a position of the lower end squeegee blade such that the lower end squeegee blade comes into contact with the panel. Cream solder dispenser equipment. 3. The cream according to claim 1, further comprising fixing means for fixing the perforated squeegee so that the lower end squeegee blade of the perforated squeegee holds a predetermined angle with respect to the panel. Solder dispenser device. 4. A piercing squeegee is made of POM or POM.
2. The cream solder dispenser according to claim 1, wherein the return squeegee is formed of a material having the same hardness as that of the urethane, and the return squeegee is formed of a material having the same hardness as the urethane. 5. The cream solder dispenser according to claim 1, wherein the perforated squeegee has a squeegee blade also at an upper end. 6. The cream solder dispenser device according to claim 1, wherein the perforated squeegee is configured as a combined perforated squeegee in which a plurality of perforated squeegees are stacked in the squeegee direction.